Photon Focus OEM-D1024E, Руководство пользователя

Страница: 32 / 69

4 Functionality
User-defined Look-up Table
In the ’User’ mode, the mapping of input to output grey levels can be configured arbitrarily by
the user. There is an example file in the PFRemote folder.
U s e r L U T
y = f ( x )
1 0 b i t
8 b i t
Figure 4.20: Data path through LUT
4.4 Test Images
Test images are generated in the camera FPGA, independent of the image sensor. They can be
used to check the transmission path from the camera to the frame grabber. Independent from
the configured grey level resolution, every possible grey level appears the same number of
times in a test image. Therefore, the histogram of the received image must be flat.
A test image is a useful tool to find data transmission errors that are caused most
often by a defective cable between camera and frame grabber.
The test images are optimised for the OEM-D1024E cameras due to the resolu-
tion that is a power of 2 (1024 x 1024 pixels). The test images of the OEM-D752E
camera contain the first 752 x 582 pixels of the OEM-D1024E test images and
therefore the histogram will not appear flat.
4.4.1 OEM-D1024E Test Images
Ramp
Depending on the configured grey level resolution, the ramp test image outputs a constant
pattern with increasing grey level from the left to the right side (see Fig. 4.21).
Figure 4.21: Ramp test images: 8 bit output (left), 10 bit output (middle), 12 bit output (right)
30